CN 201194837 Y discloses an ablation apparatus comprising a radiofrequency (RF) ablation electrode and an ultrasound unit. The ultrasound unit is used to ultrasonically sense target tissue before and/or during performing an RF ablation procedure. If the target tissue is ultrasonically sensed while the RF ablation procedure is performed, the ultrasound sensing is adversely affected by the RF energy applied to the target tissue, whereby the quality of sensing the target tissue can be reduced.